1. Field of the Invention
The present invention relates to the field of liquid crystal display, and more particularly to a circuit arrangement of a gate side fan out area.
2. The Related Arts
TFT-LCD (Thin Film Transistor Liquid Crystal Display) is one of the most major types of the present flat panel display productions and has already become an important display platform in the modern IT and video productions. In a TFT-LCD, the thin-film transistor, TFT or other active elements are employed to control every pixel unit's switching on/off and to control the light transmission rate of the liquid crystal material according to video signals for displaying images. The liquid crystal display is equipped with a display panel comprising a pixel array and a driving circuit employed for driving the liquid display panel. Multiple parallel data lines and multiple parallel scan lines are formed on the display panel. The data lines and the scan lines crisscross one another. Pixel units and TFT switches of controlling the pixel units are positioned at the crisscrosses. The driving circuit comprises a source driver and a gate driver. The source drive provides signals related with showing images to the data lines. The gate driver provides signals of switching on/off the thin film transistors to the scan lines.
As shown in FIG. 1, which is a TFT-LCD driving structure diagram according to prior art. The primary driving principle of a present TFT-LCD comprises: a system mainboard connects the lines of R/G/B compression signals, control signals and power to a connector of PCB 1. The PCB 1 connects the display area 4 via a S-COF (Source-Chip on Film) 2 and a G-COF (Gate-Chip on Film) 3. Accordingly, LCD obtains required power and signals. For realizing a narrow frame design and meeting the development of electronic products to be thinner, smaller, with better functions and faster. The package skill for the driving chips is accordingly developed toward the same way of being thinner and smaller. Both the gate chip and the source chip utilizes COF (Chip on Film) package. As shown in FIG. 1, a fan out area 5 is the part which the signal the lines of the display area 4 and the driving chip are connected. The fan out area 5 at a side of the G-COF 3 is so called a gate side fan out area.
Under the present structure, in a case of a liquid crystal display with resolution m×n, 3m source data lines and n gate scan lines are required. The necessary amounts of the data drivers and scan drivers are respectively 3m/a and n/b if the channel number of the data drivers and scan drivers are respectively a and b. The prices of the data drivers are higher than those of the scan drivers. The number of data drivers is larger and results in higher manufacture cost. A general solution is to arrange the R pixel electrode, the G pixel electrode and the B pixel electrode along the direction of the scan lines. For a liquid crystal display with the same m×n resolution, only m data lines and 3n scan lines are required. Accordingly, the necessary amounts of the data drivers and scan drivers are respectively m/a and 3n/b. The necessary number of the data drivers is reduced to ⅓. One way or another, the manufacture cost can be reduced. Nevertheless, the number of the scan drivers is tripled which cannot be beneficial for the manufacture cost.
Be that as it may, the resolution of the liquid crystal display is proportional with the number of the gate scan lines. As peaking demand regarding the resolution of the liquid crystal display, the real application requirement only can be satisfied by increasing the number of the G-COF or the number of the single G-COF output channel. Then, the manufacture cost is meant to be raised and the bonding yield is meant to be dropped.